Flow Characteristics Of Breathing Jet In The Aircraft Cabin And Its Influence On Pollutant Propagation

In recent years,with the development of civil aviation and the improvement of people’s living standard,more and more people choose aircraft for transport.However,the guest cabin is a complex space,which is closed,high density of people and high heat source.Passengers in the cabin are both sources of contaminants and sinks of pollutants.Passengers’respiration will affect the cabin’s internal environment.Therefore,the study of the laws of human breath in the cabin is very necessary.This paper uses the self-developed human breathing simulator,which is installed in the warm dummy,instead of real people breathing.The experiment is set up in a seven-bay experimental platform.PIV and INNOVA1412 are used to measure respiration flow characteristics and pollutant distribution under different working conditions.The purpose of this study is to analyze the flow characteristics of dummy breathing area and evaluate the effect of respiratory momentum on breathing zone flow characteristics and to analyze the effect of air supply and thermal plume on breathing momentum.The experimental results could be used to guide the theoretical analysis and CFD simulation,and then predict the spread of gaseous pollutants.Finally,the tracer gas experiment is carried out to verify the rule of PIV,and obtain the effect of respiratory momentum on pollutant propagation.The results show that breathing jet is influenced by various factors and the jet distance is shortened to 17.6cm,which limits the ability of the pollutants spread forward to a certain extent.It is found that the breathing zone exists counterclockwise vortex under real working conditions and the vorticity is 1.5²s^-1.This kind of vortex has a locking effect on contaminants,which can promote the downward bending of the breathing jet.By measuring and analyzing the flow characteristics of human respiration area and the law of pollutant propagation in the cabin,on the one hand,we can effectively predict the propagation characteristics of respiratory pollutants,and on the other hand,we can analyze the effect of respiration on the pollutant transmission and provide the basis for further experimental research on pollutant propagation law and numerical simulation.